Some immunological studies on a new vaccine derived from bacteriophage lysate of Pasteurella multocida in mice

The study was undertaken to evaluate the humoral immune response in mice induced by a novel phage lysate vaccine against Hemorrhagic Septicemia developed from Pasteurella multocida grown under iron-restricted conditions and lysed by a bacteriophage. Two groups of mice were immunized with lysate vaccine (LV) and conventional killed HS vaccine (CV) and blood was collected at various days post-immunization (DPI). The serum protein concentration in lysate vaccinated mice (4.675±0.223) was significantly higher (p<0.05) than the conventional vaccinated mice (4.100±0.282) at 150 DPI. The serum globulin levels at 90 DPI and 180 DPI in LV mice (1.330±0.071 and 0.650±0.100) were significantly (p<0.01) higher than the CV mice (0.850±0.084 and 0.366±0.098). The serum IgG levels at 150 DPI and 180 DPI in LV (0.564±0.188 and 0.485±0121) mice were significantly higher (p<0.01) than the CV mice (0.178±0.039 and 0.121±0.026). Although our results in mice are promising, further studies involving bovines are needed.